Applicator devices serve to apply or mount flat material elements, in particular labels, to an object. In the case of applicator devices of that nature, it is important that the applicator head holds the flat material element to be applied securely during the application procedure. This is particularly important to avoid displacement of the applicator head from a starting position, in which it picks up the flat material element to be applied, to the application location, in which the flat material element is applied to the object. In some conventional applicator devices, a suction air flow is used for holding the flat material element to the applicator head. Two different kinds of suction air applicator devices are common in these conventional devices.
The first type of suction air applicator device includes a fan that produces a suction air flow. The fan is disposed in the interior of the housing portion of the applicator device, which also accommodates a control system and a hydraulic or pneumatic displacement means of the applicator device. The applicator head has openings therethrough in its applicator surface. The flat material element is held to the applicator head by the suction air produced by the fan.
This first type of suction air applicator device, however, does not operate in a fault-free manner when dealing with flat material elements that are small and/or difficult to apply. In addition, this type of applicator device requires secondary air.
A second type of suction air applicator device is an injector applicator device. Injector applicator devices operate on the basis of the venturi principle. The applicator head is again provided with a plurality of openings therethrough, wherein an injector is disposed in the interior of the housing of the applicator device, and compressed air is jetted into the injector. This causes the air to be dragged out of the applicator head, thereby reducing air pressure in the head, so that the flat material element is held to the applicator head.
The second type of injector applicator device suffers from the disadvantage that fault-free operation is only possible when all openings in the applicator head are covered by the flat material element. A suitable applicator head, therefore, has to be produced for each form of a flat material element, which is disproportionately costly.